Replying to Question about the law..

so leme explain the story then ill ask my question...

so i went out the other night to meet up with some people..they told me where they were i pulled up to the house and one of the kids was like dude get outa here cops are coming the neighbor came over and caught us partying in this house..apparently they were in an abandoned house that was for sale so noone was there..well thats dumb ass shit but thats not what i was wondering..so a group of us got outa there..but the neighbor ended up making the other couple kids give him their keys threatening to call the cops and would not let them drive anywhere home..he was gonna have the kids that he caught confront the cops or call their parents...then he decided he wasnt gonna call the cops..so seeing that its not his house..and he wasnt getting the law involved was he allowed to take the kids keys and not let them go anywhere? or did he wrongfully take their stuff and hold them there? or was it just stupid for the kids to actually give up their keys lol..